I would like to create documentation of my fields, files, pages, filters, menus and relationships.
Before Knack, I used MS Access to build apps for clients. That system lets you print a diagram showing tables with connections and one to many symbols on the connection line. The tables show the fields listed and the connection lines show visually which specific field connects to the other tables. At a more detailed level you can print reports which shows for each field all the attributes, defaults, calculations, etc. In Knack terms, I want documentation for each page and each report as well; such as filters, sorts, data sources, etc.
With those kinds of documentation I can train people, avoid design and enhancement errors, even hire and direct Knack developers much easier than just letting them wander around in the application.